Artificial tooth.



L. E. EVSLIN.

ARTIFICIAL TOOTH.

APPLICATION FILED 050.215.1911.

Patented Jan. 28, 1919.

WITNESSES:

M'r/QM ATTORNEYS UNITED STATES PATENT OFFICE.

LEO EVSLIN, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TOHDORA. STALBERG, OF PHILADELPHIA, PENNSYLVANIA.

nnmrcmr. roo'rH.

Specification of Letters Patent.

Patented Jan. 28, 1919.

To all 'whom it may concern:

Be it known that I, Lno E. EVSLIN, residing at New York, in the county and State of New York, have invented certain new and useful Improvements in Artificial Teeth, of which the followin is a specification.

This invention relates to improvements in artificial teeth, and more particularly to artificial teeth of that class comprising a porcelain facing and a backing which may be detachably secured together.

One of the objects of the invention is to produce a tooth of this character wherein the backing is disposed over the cutting edge of the porcelain to relieve the latter of biting strains, the parts being of such structure that the facing may be properly fitted to the backing before the parts are finally secured together, and sothat the facing may be retention between backin placed by another facing interchangeable with it when occasion arises. v

Another object of the invention is to provide a orcelain facing having a groove of a partic ar kind therein for the reception of a correspondingly shaped pin to which the backing may be first temporarily secured, the arrangement of parts being such that when the backing is temporarily secured to the pin, with the protecting tip of the backing extended over the incisive edge of the facing, with the pin engaged in the groove of the facin as in the final relation of parts, the pin wit the attached backing'may be readily removed from the facin and assembled therewith again without dlsturbing the fit of the backin relatively to the facing and articularly t e' fit of the protectin tip of t e backing to the incisive edge 0 the facing. 1

Another object is to provide a facing and ap ropriate pin of such construction and relation that a backing ma be adapted to the .i'acing which will afior great strength to the assembled structure and maximum reand'facing.

Other objects and aims of the invention more or less broad than those stated above will be in part obvious and in Part specifically referred to in the course 0 the following description of the elements, combinations, arrangements of parts, and applications of rinciples constituting the invention; and the scope of protection contemplated will appear from the appended claims.

In the accompanying drawings, which are to be taken as a part of this specification, and in which I have shown merely illustrat1ve forms of embodiment of the invention;

Flgure 1 is a section of a facing which may be employed in connection with my invention;

F1g. 2 is a view of a pin adapted to be used in connection with the facing shown in Fig. 1, showing also in section a backing adapted to be connected with said pin;

Fig. 3'is a view of a facing such as shown in Fig. 1 in connection with a pin and back ing such as shown in Fig. 2, the backing being shown connected to the pin, and the pin just entering the groove of the facing;

Fig. 4 is a view similar to Fig. 3, but showing the in about half way in the groove of the acing;

Fig. 5 is a view' slinilar to Fig. 4, showing the pin in position in the groove and the backing in its proper relation to the beveled incisive edge of the facing;

Fig. 6 is a detailed perspective of a pin such as may be used in connection with my invention;

Fig. 7 is a detail perspective of a boxing such as ma define a groove in the facing of a tooth em odying my invention;

Fig. 8 illustrates how my invention may be applied in connection with molar teeth;

Flgure 9 illustrates a modified form of the invention shown in Figs. 1 to 8.

Referring to the numerals on' the drawings, and particularly to Figs. 1 to 9, inclusive, 1 indicates a facing for a tooth embodying m invention, the formof tooth illustrated being a bicuspid. As shown, the opposite ends of the tooth are preferably beveled, the upper or cervical 'edge as at 2, and the lower or biting edge, as at 3. There is a pin socket or groove 4 opening into the back of the facing 1, and preferably defined by a boxing shown in Fig. 7 baked into the'material of the facing during the manufacture of the latter. Preferably, for purposes hereinafter explained, the inner wall 5 of the groove is, at least throughout a part of its length, curved on the arc of a circle, and preferably also sa1d groove terminates adjacent the biting edge of the facing in the socket 7, which 15 tapered as shown. 8 indicates a pin, preferably havin milled sides, and havlng a face 9,

. cum to correspond with the curve of the inner wall of the groove in the facing, and having preferably a tapered end 10 to correspond with the end of the socket in the facing. The pin is also provided with an attaching portion 11, which is adapted to extend through an aperture 12 in the backing 14. In practice the pin is slipped into the groove of the facing, and the backing prepared with the aperture 12 is engaged over the attaching portion of the pin, and then the backing is swaged into shape over the facing, so that the backing will have portions 15 and 16 engaging the bevels of the cervical and incisive edges of the facing respectively. The backing is now temporarily secured in its desired fixed relation to the pin by means of wax or the like, and it will be apparent that the pin may be withdrawn from the facing, carrying the backing with it, and brought back to place again asoften as may be desirable or necessary in the course of the manipulations attending the particular operation, the portion of the backing which engages over the bevel of the biting edge going readily to place, as indicated from Figs. 3, 4 and 5, so that the backing needs to be shaped to the facing but once, and that at the beginning of the mechanical operation. This result follows from the fact that the inner wall of' the groove in the facing and the surface of the pin that slides on said wall are curved on the arc of a circle.

It will be evident that many of the details of this invention may be varied and are not of the greatest importance. For instance, I have shown the groove in the facing defined by the boxing shown in Fig. 7 as of a dove tailed cross section. Obviously it might just as well have a circular or other similar undercut cross section or a cruci-form or T cross section or the like,

so long as the surfaces of the groove andof the pin which determine the direction of movement of the pin within the groove are upon the arc of a circle. Obviously too, in the case of such change in the cross section of the groove the shape of the pin Referring to the modification shown in Fig. 9, the structure is like that already described, except that the posterior surface of the facing 1s on a curve, substantially as shown, extending from the cervical to the biting edge. The pin and the groove are as in the figures already described.

It is particularly desirable that the facing shown in this figure have its posterior surface, extending longitudinally from some point, as 17, to the incisive edge 18, curved on an are parallel to' the arc of the pin groove. With such an arrangement, the mere fitting of the facing with a-backing provides at the same time a selfprotecting tip, without the necessity for grinding in order to produce the same. In this form of construction also the manipulation of the parts is facilitated,- while the assembled structure possesses great strength. I 1

As many changes could be made in this construction without departing from the scope of the following claims, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative only and not in a llmitingsense.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. An artificial tooth member having a guide portionformed longitudinally alongits inner surface, and said guide being curved longitudinally of its length, a backing for said tooth member, and means connected with said backing having a curved surface adapted to slide along said curved guide whereby to direct said backing to a predetermined position ,up'on said tooth member.

2. An artificial tooth member having a guide formed longitudinally along its inner surface, said guide being of substantially uniform cross section throughout its length, and being curved longitudinally in a path convex to the rear surface of said tooth member, a backing for said tooth member, means connected with said backing adapted to slide along said groove in a curved line defined by said groove to direct said backing to a predetermined osition upon said tooth member, and saif means and said guide having cooperative formations for preventing lateral displacement of said means from said guide during any relative longitudinal movement between them.

3. An artificial tooth member having a guide portion formed longitudinally along its inner surface and said guide being of substantially uniform cross section throughout its length and being curved convex to the rear surface of said tooth member longitudinally and uniformly in the arc of a 126 circle continuously throughout its length, said tooth member being formed with a socket-like portion adjacent the incisive edge thereof nto which one end of said curved guide terminates, a backing for said tooth 130 member, and means connected ,with said backing curved lon 'tudinally to correspond to the curvature 0 said guide so as to be slidable alon with said guide andhaving a ortion a apted to engage within said 800 et.

4. An artificial tooth comprising a facing provided with a groove extending along its lnner surface, the bottom wall of said groove.

being curved longitudinally in the';arc of a circle, a pin slidable in said groove having a surface curved on the arc of a circle engaging the curved wall of said groove to be guided in a curved path thereby, a backing carried by said 1n for engaging the innersurface of said acing, said facing being beveled ofi at one end, and said back ing having a portion for engaging the bevel of said facing.

5. An artificial tooth comprising a facing provided with a groove extending vertically along its inner surface, said groove opening at one end through one of the end surfaces of the facing, the bottom walls of said groove being curved on the arc of a circle, a pin slidable in said groove having a'curved surface engaging the curved wal of the groove to be guided thereby, and a,

backing carried by sald pin.

6. An artificial tooth comprising a facing provided with agroove extending alon its inner surface, the bottom wall of sai groove bein curved longitudinally in the arc of a circ e, the side walls of said groove being undercut to provide relative shoulder portions longitudinally of the groove, a pin slidable in said groove having a surface curved on the arc of a circle engaging the curved bottom wall of the groove to be guided in a curved path thereby, saidpin also having shoulder portions to engage the shoulder ortions of the oove to retain the curved surface of the pin in engagement with the curved wall of the groove, and a backing carried by said pin.

7. An artificial tooth comprising a facing provided with a groove extending along its inner surface, the bottom wall of, sai

groove bein curved longitudinally, in the arc of a circ e, a pin slidable in said groove having a surface curved'on the arc of a circle engaging the curved wall of said roove to be guided in a curved path therey, and the inner surface of said facing adjacent one end thereof being disposed in a plane substantially parallel to the plane of the bottom wall of the adjacent end of said groove, for the purpose set forth.

8. A tooth having an approximately vertical and flat lingual surfaceand a gingival margin or surface slopin from the lingual surface to the labial sur ace of the tooth; also said tooth provided with a curved recess or cavity which opens out of the lingual surface and the gingival margin.

9. A tooth having a curved recess or cavity which opens out of the lingual surface and gingival margin, the upper wall of the recess or cavity extendin in the direction of the incisaledge; a backmg for said tooth; and a curved pin for uniting the tooth to the backing, sad in adapted to have a slidable relation in 't e recess or cavity, entering the recess or cavity at the gingival margin of the tooth.

10. A tooth or facing having a curved recess or cavity opening out of the lingual surface and also its gingival margin; said recess or cavity being wedge shaped in cross section; a wedge shaped pin curved throughout its length conforming to and adapted to enter and fit the recess or cavity in said tooth or facing, said pin having a head; and backing for the tooth provided with an opening to receive the head of the pin.

In testimony whereof I afiix my signature in the presence of two witnesses.

LEO E. EVSL IN.

Witnesses:

FRANK J. KENT, NATHALIE THOMPSON. 

